1. Field of the Invention
The present invention relates to a method for performing data communication, and more particularly, to a method for determining a traffic priority order on a network that is suitable for efficient data transmission in accordance with multimedia data characteristics and normal data characteristics, regardless of increases in local area network (LAN) traffic.
2. Discussion of the Related Art
Recently, due to increases in the amount of traffic communicated over networks, rapid increases in load have been experienced. Consequently, delays have been experienced in transmissions of multimedia data, such as moving picture data, which require real time processing.
Conventional networks typically communicate data based on a first-in-first-out protocol. A conventional method fox determining a priority order for traffic communicated over a network will be described with reference to the accompanying drawings.
FIG. 1 is a schematic block diagram illustrating a relationship between a switching hub and respective stations on a network. As illustrated in FIG. 1, the network includes a switching hub 11 and a plurality of stations 12 that are connected to the switching hub 11 for data communication. stations 12 that are connected to the switching hub 11 for data communication.
Software 11a is mounted in the switching hub 11 to control the hub. The software 11a transfers data received from a source station 12 to a random destination station in accordance with a priority order.
A network interface card (NIC) 12b and a software driver 12a are mounted in each station 12. The NIC 12b enables data communication with the switching hub 11. The software driver 12a controls the NIC 12b.
As illustrated in FIG. 2, the switching hub 11 includes a memory 11b for temporarily storing data received from a source station 12, a controller 11c for controlling the memory 11b, and a plurality of Ethernet interfaces 13 connected in parallel to the controller 11c for converting data to comply with a protocol for data communication between source and destination stations 12. The Ethernet interfaces 13 convert data received from the software driver 12a, which is mounted in the respective station 12, into a format complying with Ethernet protocol.
The operation of the aforementioned network will be described below.
When data is simultaneously transmitted from stations A and C to station B, the switching hub 11 initially transfers data from only station A to station B. The data transferred from station C is temporarily stored in the memory 11b and subsequently transferred to station B after the transmission of data from station A to station B has been completed.
On the other hand, if the data transferred from station A has been temporarily stored in the memory 11b, data can be transferred from station C to station B prior to transmission of the data stored in memory 11b. When data transmission from station C to station B is completed, the data from station A that has been stored in the memory 11b can be transferred to station B.
Priority order that is used to control whether data from station A or station C will be given priority for transfer to station B is determined based on the sequence of data received by switching hub 11.
FIG. 3 is a flow chart illustrating a conventional method for determining a traffic priority order for a network. As illustrated in FIG. 3, data that is received by the memory 11b from a plurality of stations 12 (101) is read in the sequence received.
It is then determined whether or not a destination station can receive data (102). If the destination station can receive data, the data read from the memory 11b is transferred to the destination station (103). It is then determined whether or not the transmission of data being transferred in step 103 has been completed (104). If not completely transmitted, data transmission continues Once completely transmitted, data subsequently received by the memory 11b is read (105).
The data transmission between the respective stations can be performed by the above-described steps.
However, the conventional method for determining traffic priority order on a network has several problems. For instance, when the data processing is performed based only on the sequence of arrival to the memory, without regard for regular priority order, urgent and non-urgent multimedia data are not distinguished. Consequently, unacceptable delays are experienced by urgent multimedia data. Specifically, data that requires real time processing is not given priority over other less urgent data, such as E-mail that does not cause any problems even if data transmission is delayed are processed. For this reason, problems are experienced in real time processing of multimedia data, diminishing network efficiency.